The present disclosure relates to rotor systems for helicopters and similar aircraft, and in particular to tail rotors.
Helicopters are flying machines which can fly in any direction or hove over a point on the ground without moving. Helicopters usually have a single main rotor mounted on top of a body or fuselage of the helicopter to generate a lift force to hold the helicopter in the air, and a tail rotor or other yaw control system to maintain directional control of the helicopter. Several different yaw control systems have been developed (such as blown tail booms and shrouded fans), but traditional tail rotor systems with exposed tail rotor blades are still the most popular.
With all of their rotating rotor blades, gears, and mechanical linkages helicopters are typically more complicated and expensive than other types of aircraft such as fixed-wing airplanes. Helicopters are also generally more difficult to fly than airplanes, and model helicopters are particularly difficult to control. As a result, pilot of model helicopters frequently crash and damage their models. Model helicopters can be very expensive to repair, so relatively few modelers have the patience, skill, and budget to master them. Components that reduce the complexity and cost of helicopters make helicopters more available to the general public, easier to maintain and repair, and generally more competitive with other types of aircraft.
Tail rotor systems on helicopters are extremely important because the control the direction of flight. Tail rotors are also more likely to be damaged than other parts of a helicopter because they are often operated near obstruction such as trees or the ground, and are lightly constructed to prevent a tail-heavy condition of the helicopter which would adversely affect the helicopter in flight. Impact of the tail rotor blades on an obstruction can cause the helicopter to loose control and crash. Tail rotor failure and tail blade strikes, on obstructions are one of the most common types of helicopter accidents which lead to personal injures of the pilot and bystanders and loss of the helicopter. What is needed is a tail rotor system that is simple, inexpensive and less susceptible to damage.
According to the present disclosure, a helicopter tail rotor system comprises a tail boom, a gear box associated with the tail boom, and tail rotor blades mounted for rotation relative to the gear box. The tail rotor system further comprises a retainer configured to move in a retainer aperture provided in the gear box to engage and deform the tail boom to retain the gear box in a mounted position on the tail boom. Thus, a method is disclosed herein for moving a retainer relative to a gear box to deform the tail boom to secure the gear box in a fixed position on the tail boom.
In illustrative embodiments, the gear box includes a gear box housing formed to include the retainer aperture and a rotatable bevel gear mounted for rotation in the gear box housing and coupled to rotate with a rotatable drive shaft extending through the tail boom. The tail rotor blades are adapted to rotate in response to rotation of the drive shaft and the bevel gear coupled to the drive shaft. The retainer is used to retain the gear box housing in a fixed position on the tail boom without hindering rotation of the drive shaft in the tail boom or the bevel gear in the gear box housing.
Additional features of the disclosure will become apparent to one skilled in the art upon consideration of the following description of the various embodiments which illustrate the best mode for carrying out the disclosure as presently perceived.